Directional-flame burner



4 Sheets-Sheet 1 Filed July 19, 1952 m? NT Q .m 3 w m N Qm R. 5N Om RV Qm wv 0m V WM 0 Q o \v NM. 7 o '1 mm, a m z INVENTOR OLL/SON CfiH/G BY MATTORNEY Aug. 21, 1956 o. CRAIG DIRECTIONALJ'LAME BURNER 4 Sheets-Sheet2 Filed July 19, 1952 INVENTOR OLL/SON CRA/q m X 4M ATTORNEY Aug. 21,1956 o. CRAIG 2,759,460

' DIRECTIONAL-FLAME BURNER Filed July 19, 1952 4 Shets-Sh eet 5 INVENTOROz. 1. lso/v CRA/G BY W154i ATTORNEY Aug. 21, 1956 o. CRAIG 2,759,460

DIRECTIONAL-FLAME BURNER Filed July 19, 1952 4 Sheets-Sheet 4 INVENTOR01.4 lso/v 61mm ATTORNEY United States Patent DEREQTIONAL-FLAME BURNEROllison Craig, Worcester, Mass, assignor to Riley Stoker Corporation,Worcester, Mass., a corporation of Mars sachusetts Application July 19,1952, Serial No. 299,888

3 tilaims. (Cl. 122-333) This invention relates to directional-flameburners and more particularly to fuel burning apparatus for use in thefurnace of a steam generating unit.

In the burning of fuel for the generation of steam it is often desirableto provide for adjusting the direction of the flame. This isparticularly true in the burning of fuels burned in suspension where thefuel and air are projected into the combustion chamber with great force,so that the flame is very long. By adjusting the direction in which theflame extends, it is possible to control superheat, among other things;the adjustment of the flame to various directions in a vertical planewill change the temperature of the gases which pass into the convectionpasses of the boiler. Changing the direction of the flame also producesa change in the manner in which the products of combustion swirl andflow in the combustion chamber. Burners have been used in the past inwhich the flame produced is adjustable angularly, but these prior-artdevices have suffered from many disabilities. For one thing, they cannotbe used without disturbing the water-wall tubes in the furnace wall;bending the tubes to provide an opening for the burner is expensive anddeprives the furnace wall of a large radiation area. Also, thepreviously known burners of this type have been very expensive, aparticularly undesirable feature in installations where the burner isonly intended for intermittent use as an auxiliary to separate burnersusing other types of fuel. In many cases the mixing is poor, resultingin poor combustion and low efficiency as well as smoking. Also, many ofthese devices may lose ignition during changes in flame direction. Thepresent invention obviates the shortcomings and the difiicultiesencountered in the prior art in a novel manner.

It is therefore an outstanding object of the present invention toprovide a directional-flame, intertube burner which is simple inconstruction and inexpensive to manufacture.

Another object of the invention is the provision of a fluent fuel burnerin which mixing of the fuel and the combustion air is very thorough.

A further object of the instant invention is to provide an intertubeburner which permits adjustment of the length and angular direction ofthe flame.

Another object of the invention is the provision of a burner for fluentmaterial which permits changes of angularity of the flame without dangerof loss of ignition.

A still further object of the invention is the provision of an intertubeburner which is very rugged and which will give a long life of usefulservice.

It is another object of the invention to provide an intertube burnerwhich permits the burning of a number of fuels in the same portion ofthe furnace.

A further object of the present invention is the provision of anintertube burner in which the water wall tubes of the furnace are onlyslightly disturbed and are subject to very little loss of radiant heatfrom the furnace because of rearrangement.

Another object of the invention is the provision of a'di- 2,759,460Patented Aug. 21, 1956 rectional-flame burner construction wherein vanescontrolling the gas flow can be located between the tubes and rigidlysupported in that position.

With these and other objects in view, as will be apparent to thoseskilled in the art, the invention resides in the combination of partsset forth in the specification and covered by the claims appendedhereto.

The character of the invention, however, may be best understood byreference to certain of its structural forms, as illustrated by theaccompanying drawings in which:

Figure 1 is a vertical sectional view of a burner embodying the presentinvention taken centrally thereof and longitudinally of the furnace,

Figure 2 is a vertical elevational view of the burner looking fromwithin the furnace,

Figure 3 is a horizontal sectional view slightly reduced in size of aportion of the burner taken on the line 3-3 of Figure 2,

Figure 4 is a vertical elevational view of the burner showing itsexternal appearance when looking toward the furnace,

Figure 5 is a view of a mechanism used with the burner as it appearswhen looking along the line 55 of Figure 2, and

Figure 6 is a vertical sectional view of a modification of theinvention.

Like reference characters denote similar parts in the several figures ofthe drawings.

For the purposes of the discussion which follows, the portion of thefurnace wall in which the apparatus resides will be thought of as thefront wall, so that the expression longitudinal will mean perpendicularto the wall, the expression transverse will mean parallel to the wall,the expressions inner or forward will mean toward the inside of thefurnace wall, and the expressions outer or rearward will mean toward theoutside of the wall. This is not meant to imply, however, that theburner could not be used as Well in connection with the other walls ofthe furnace.

Referring first to Figure 1, wherein is best shown the general aspectsof the invention, the burner, generally designated by the referencecharacter 10 is shown in use with the water wall tubes 11 of the furnaceof a steam generating unit. Although the furnace wall is not shown, itis to be realized that the water wall tubes normally reside inside-by-side relation on the inside surface of the wall and that anopening in the wall must be provided for the apparatus of the invention.In the present embodiment of the invention, two vertical water walltubes 11 are bent rearwardly and laterally to form vertically elongatedopenings or slots 12 (see Figure 2). The two tubes so bent reside behinda third tube which is not bent, so that in the area of the burner and ofthe opening in the furnace wall, the water wall tubes are arranged inrows of three aligned longitudinally of the furnace. At the upper andlower extremities of the opening in the furnace wall are providedtransverse channels 13 and 14. These channels are rigidly connected tothe tubes 11 by means of clamp members 15. The clamp members arearranged in pairs, each pair embracing a row of tubes 11; the facingsurfaces of each pair are formed with vertical cylindrical grooves 16(see Figure 3). A pair of opposed grooves 16 embrace each tube and abolt 17 is provided to join each pair of members 15 in clamping relationto the rearward two tubes 11. The forward end of each clamp member isprovided with a horizontal medial slot 18 and the portions of the memberwhich lie above and below this slot are joined to similar portions ofthe opposing member by bolts 19 and 20, respectively. The rearward end.

of each clamp member 15 is bolted to its respective channel 13 or 14. Onopposite sides of the burner reside vertical side plates 21 which arefastened to the channels 13- 3 and-.14 and extend forwardly to the inneredge of the opening in the furnace wall. There is a pair of clampmembers associated with each row of tubes 11 across the top and bottomof the burner, the two transverse rows of clamp members thus beingcoextensive with the channels 13 and 14. Between the bottom pair ofclamping members and the top pair associated with each row of tubes 11.are situated a series of generally similar clamp members 22 which differfrom the members 15 only in that their rearward endsare notconnected tostructural members and are formed to present a smooth, rounded surfaceto the flow offuel. The clamp. members 22 are similar to the clampmembers 15 in that they are provided with slots 23 and each pair is heldtogether by bolts to embrace the three tubes which extend therebetween.The upper and lower edges of the clamp members 15 and 22 are formed withsemi-circular notches 24, each notch cooperating with a similar notchonthe adjacent clamp member to form a circular aperture, extendinghorizontally through the rows of clamp members. Through these aperturesare passed the shafts 25 of adjustable vanes 26 which may have alongitudinal slot entering the forward edge In the present embodiment,three slots 12 are provided between the Water Wall tubes and a verticalrow of three vanes resides in each of the outer two slots; in the centerslot, however, there are only two vanes, one in the upper portion andthe other in the lower portion. The purpose of the omission of a vane inthe central portion of the burner is to permit the insertion of asupplemental burner, as will be described hereinafter. The shafts 25 onwhich the vanes are mounted are connected together for simultaneousmovement in a manner which will be described more fully hereinafter.

Extending rearwardly from the rear ends of the clamp members is atubular mixing housing 27 of square crosssection, defining a mixingchamber 28 the forward end of which fits snugly into the square openingdefined by the channels 13 and 14 and the side plates 21. The forwardedges of the housing are welded or otherwise secured to the channels 13and 14 and the side plates 21. Into the rearward end of the housing issnugly fitted a short tube 29 of circular cross-section, the diameter ofthe tube being of such a size that the sides of the housing 27 aretangential to the wall of .the tube at four points in its circumference.The tube 29 is capable ofsliding movement in and out of the housing 27and is held in a selected position by set screws. or the like, notshown. Since the tube 29 is of circular cross-section while the housing27 is of square cross-section, fourfillers 34) are provided to fill theareas in the corners of the housing which lie outside the.axialprojection of the tube into the housing. Mixing vanes 31 are weldedto the tube 29 and extend inwardly thereof; these vanes are arrangedgenerally helically of the axis of the tube. Fastened to the rearwardend of the housing 27 completely surrounding the tube 29 is a secondaryair housing 32 of generally box-like configuration; the housing 32 isprovided with a square opening in the forward side, the edges of whichare welded or otherwise fastened to the rearward end of the mixinghousing 27. The upper side of the housing 32 is open and is connected toa source of secondary air, not shown, in a wellknown manner. Residingwithin the housing 32. near the upper opening are secondary air vanes 33mounted on horizontal transverse shafts 34 the ends of which are keyedexternally of the housing. 32 to crank arms 35 which, in turn, arepivotally connected to an actuating bar 36. The actuating barv 36extends rearwardly of the housing. and is pivotally connected to a crankarm 37 which is keyed at its other end to a shaft 38 which isjournaled-to the rearward external surface of the housing. The shaft 38is keyed to the vertexof a gear segment 39 which is actuated by a worm40 which is rotated by a hand wheel 41. A seriesof peep holes, 42 enterthe reaward side of the housing 32 and-are spaced about the axis of thetube 29.

A cir cula 1: opening 43 vis formed-,inthe rearward side of the housing32concentrically with the axis of the tube 29. In this opening 43 isfastened one end of a tubular flange member 44 which extends rearwardlyfor some distance. To the other end of the flange member id is fasteneda fuel housing 45 which consists of a generally tubular portion coaxialwith the tube 29 and another tubular portion which extends at a rightangle thereto. Generally speaking, one end of the coaxial tubularportion constitutes the outlet and is fastened to the flange member,While the outer end of the non-coaxial tubular portion is the inlet andis fastened to a source of fuel, not shown. Within the housing 45 andarranged around the axis of the tube 29 is a series of vanes 46 whichare mounted on shafts 47 which extend parallel to the axis. The shafts47 are mounted on and extend through the rearward surface of the housing45 and are provided with means, such as nuts 43, for locking the vanesin selected positions of adjustment. Extending through this same side orwall of the housing 45 and mounted thereon is an auxiliary burner, suchas the igniter 49. This igniter resides concentrically of the axis ofthe tube 29 and extends throughout the entire length of the burner,ending between the rows of water wall tubes 11. Its rearward end residesexternally of the housing 45, as has been stated, and is provided withsuitable connections for oil, gas, or the like. A tube 50 of circularcross-section extends from the inner surface of the flange member 44 toa position adjacent the vanes 31 in the tube 29. The tube 50 isconcentric with the igniter 49 and at the forward end, in the annularspace between the tube and the igniter, are fastened helical fuelspreading vanes 51.

Referring to Figure 4, it can be seen that the external appearance ofthe invention is articularly well shown. The arrangement of the shaft 38transversely across the front of the housing 32 is shown as well as itsconnections with the crank arm 37 and the actuating bar 36. The handwheel41 is mounted for easy access. This view shows the arrangement ofthe peep holes 42 around the housing 45 and it also shows the concentricarrangement of the vane shafts 47' and their nuts 43. This view showsclearly the relative transverse extents of the housing 32 and the actualburner area, as represented by the channel 14.

An examination :of Figure 2 indicates that, because of the presence ofthe igniter 49, it is not possible to use a single shaft in mounting thecentral horizontal row of vanes 26. For that reason, individual stubshafts 52 and 53 are. mounted in each of the side openings 12, each suchshaft supporting one vane 26. However, this arrangement necessitates ameans for rotating the shaft 53; this is because all the other shaftsextend from a common side of the burner, but the shaft 53 extends onlyfrom the opposite side of the burner from said common side (the righthand side in Figure 2). The mechanism used to rotate the shaft 53 at thesame time as the other shafts 25 and 52 is shown in Figure 2, but isbest shown in Figure 5. Anactuating crank arm 54 is keyed to the outerend of the stub shaft 52 and is provided with an aperture 55 at itsouter end for attachment to a power cylinder or like actuating .device.The shafts are shown passing through bearing blocks 56 attached to theside plate 21. Keyed to the shaft 52 between the crank arm 54 and itsbearing block are two crank arms 57 and 58. Keyed to the outer ends ofthe upper and lower vane shafts 25 are crank arms 59 and 60,respectively. The crank arm 58 is operatively joined to the crank arm 59by an arcuate connecting link 61, while a similar connecting link 62joins the crank arm 57 to the crank arm 60. Referring again to Figure 2,the upper vane shaft 25 is operatively joined to the stub shaft 53through the medium of a crank arm 63 keyed to the shaft 25, a crank arm64 keyed to the shaft 53 anda connecting link 65 joining the outer endsof the crank arms 63 and64.

The operation of the apparatus of the invention will be evident from theabove description. The igniter 49 is fired in preparation for theintroduction of the fuel to the main burner. The secondary air vanes 33are opened to a desired setting and the air flows into the housing 32and enters the rearward end of the tube 29 and flows forwardlytherethrough. The secondary air strikes the vanes 31 and they are forcedinto a swirling motion. The fuel, such as pulverized coal, is introducedinto the housing 45 along with the proper amount of primary air. Thevanes 46 tend to introduce a swirling motion about the igniter 49 withinthe tube 50 and to promote proper mixing of fuel and air. The fuel movesforwardly through the tube 50 and strikes the fuel spreading vanes 51.In the chamber 28, therefore, the secondary air which is in a swirlingcondition and moving forwardly is mixed with the fuel and primary airwhich is not only swirling, but has a definite radial motion in additionto its motion toward the furnace. By the time they reach the vanes 26,the fuel, primary air and secondary air are thoroughly mixed. Themixture passes over the vanes 26 and burns inside the furnace. Theamount of inclination of the vanes 26 to the axis of the burnerdetermines the inclination of the center line of the flame to thehorizontal and, at the same time, influences the shape, length, andluminosity thereof. When it is desired to change a quality of the flame,for instance, the inclination or tilting, it is only necessary to adjustthe vanes 26. In the burning of pulverized coal, it is necessary topresent an inclined plane and edge to the fuel flow in order to maintainignition. This is probably because of the vortex formed by the passageof a gas or fluid over such an edge. In any case, the present apparatusis arranged with the various rows of vanes which reside at differentangles in the intermeo diate position of the flame. In Figure 1, whichshows the position of the vanes when the flame is directed generallyhorizontally, it can be seen that the upper row is inclined upwardly,while the lower row is inclined at an equal angle downwardly. Theintermediate row 66 extends more or less horizontally. When the flame isdirected upwardly at its greatest angle, the vanes are all parallel anddirected upwardly; when the flame is directed downwardly at its greatestangle, the vanes are also parallel and directed downwardly. This meansthat means is provided for moving the shafts on which the vanes aremounted at different rates of rotation. When the flame is being movedwithin the range from the intermediate position to the uppermostposition, the intermediate vanes have a greater angular change to make,while the lower vanes have an even greater angle to travel through; therates of rotation of the respective shafts are in a corresponding ratio.The same situation exists in the range from the intermediate position tothe lowermost position, the rates of rotation in this case being exactlyreversed, of course. The net result is that, when the vanes are movedfrom one setting to another in order to change the direction of theflame, there is never a time when all the vanes extend horizontally andparallel to the flow of fuel and air in the chamber 28; this means thatthere is always a set of vanes which are inclined to the flow and whichwill retain ignition. When it is desired to change the setting of thevanes 26, it is only necessary to move the actuating crank arm 54 asufficient amount. To move the vanes upwardly, the crank arm 54 is movedin a counter-clockwise direction (Fig. and this produces a certainangular rotation of the stub shaft 52 and produces in the range fromintermediate to uppermost position of the flame a somewhat lesserrotation of the upper shaft 25 through the medium of the crank arm 58,the connecting link 61, and the crank arm 59. A somewhat larger rotationof the lower shaft 25 is brought about through the crank arm 57, theconnecting link 61, and the crank arm 60. The rotation of the uppershaft 25 produces an angular rotation of the stub shaft 53 equal to thatof the shaft 52 through the medium of the crank arm 63, the connectinglink 65, and the crank arm 64.

Referring next to Figure 6, wherein is shown a modified form of theinvention, the burner 110 is shown in use with the water wall tubes 111of a furnace. Supporting channels 113 and 114 extend above and below,respectively, the general burner area. Upper and lower rows of clampingblocks 115 are fastened to the water wall tubes by means of bolts 117,119 and 120, there being slots 118 between the latter two bolts.Vertical side walls 121 extend between the channels 113 and 114, whilethe clamping blocks are also fastened to the said channels. Intermediateclamping blocks 122 are supported only by being clamped to the waterwall tubes, but are provided with generally horizontal slots 123. Eachintermediate block is provided at its rearward portion with a separableblock bearing 124 in which are rotatably mounted the shafts 125 of vanes126. Each vane 126 is of generally airfoil cross-sectional shape and ismounted along its rearward edge on the respective shaft 125. It is to benoted that the slots 118 and 126 in the blocks 115 and 122,respectively, are formed discontinuously and are made up of a series ofsurfaces arranged at various angles with respect to each other. In thesame way, the adjacent upper and lower edges of the blocks are formedwith the same zig-zag conformation, as is evident from the drawing. Theremainder of the present embodiment of the invention is substantiallylike that of Figure 1. A housing 127 extends rearwardly from thechannels 113 and 114 and the side plates 121 and merges with a secondaryair housing 132. The housing 132 has vanes 133 mounted and controlled inthe manner shown in connection with the embodiment of Figure 1. A fuelhousing extends rearwardly from the secondary air housing 132 and isoperatively joined to the interior of the housing 127 by means of a tube150. Vanes 146 control the flow of fuel and primary air through thehousing 145. The operation of this embodiment is substantially like thatof the burner of Figure 1. In the present embodiment, it is possible toreplace the vanes 126 if they become worn by merely removing the housing127 and unbolting the bearing blocks 124, whereupon the shafts 125 andthe vanes 126 can be removed and replaced. Also, the zig-zagconformation of the slots 118 and 123 and the spaces between theadjacent blocks does not allow leakage of fuel, such as pulverized coal,through passages which are not under the control of the vanes 126.Instead, the coal will pack into these spaces and form a hard seal, sothat fuel flow must take place through the main passages and becontrolled by the vanes. The aforementioned slots and spaces are, ofcourse, necessary because of the growth at elevated temperatures of thematerial from which the blocks are formed.

It is obvious that minor changes may be made in the form andconstruction of the invention without departing from the material spiritthereof. It is not, however, desired to confine the invention to theexact form herein shown and described, but it is desired to include allsuch as properly come within the scope claimed.

The invention having thus been described, what is claimed as new anddesired to secure by Letters Patent is:

1. In combination with a furnace wall having an opening therethrough, arow of spaced upright water wall tubes adjacent the furnace side of thewall, certain of the tubes crossing the opening and being arrangedparallel to one another in groups, a vertical plane which passes throughthe tubes in a group being perpendicular to the furnace wall, therebeing at least two closely-spaced tubes in each group, the groups beingspaced apart to provide a plurality of vertically-elongated slots, meansto deliver air and fuel forwardly through the opening to the said slotsand thence through the slots into the furnace, a block on each side ofeach group of tubes, blocks on opposite sides of the same group beingjoined for clamping the group therebetween, bearings associated with theblocks, horizontal shafts mounted in the bearings, and vanes residing inthe slots and mounted on the shafts.

2. In combination with a furnace wall having an opening thereth-rough, arow of spaced upright water wall tubes adjacent the furnace side of thewall, certain of the tubes crossing the opening and being arrangedparallel to one another in groups, a vertical plane which passes throughthe tubes in a group being perpendicular to the furnace wall, therebeing at least two closely-spaced tubes in each group, the groups beingspaced apart to provide a plurality of vertically-elongated slots, meansto deliver air and fuel forwardly through the opening to the said slotsand thence through the slots into the furnace, vanes residing in theslots, horizontal shafts on which the vanes are mounted, means foractuating the shafts, the vanes being mounted on the shafts in such amanner that at no time are all the vanes simultaneously parallel to thedirection of approach of air and fuel to the vanes, two blocks arrangedone above the other on the same side of a group of tubes and partiallyembracing the tubes, a bearing formed in the adjacent edges of theblocks, a horizontal shaft mounted in the said bearing.

3. In combination with a furnace wall having an opening therethrough, arow of spaced upright water wall tubes adjacent the furnace side of thewall, certain of the tubes crossing the opening and being arrangedparallel to one another in groups, a vertical plane which passes throughthe tubes in a group being perpendicular to the furnace wall, therebeing at least two closely-spaced tubes in each group, the groups beingspaced apart to provide a plurality of vertically-elongated slots, meansto deliver air and fuel forwardly through the opening to the said slotsand thence through the slots into the furnace, vanes resting in theslots, horizontal shafts on which the vanes are mounted, means foractuating the shafts, the vanes being mounted on the shafts in such amanner that at no time are all the vanes simultaneously parallel to thedirection of approach of air and fuel to the vanes, a block fastened toone side of a group of tubes and partially embracing the tubes, abearing formed on the portion of the block away from the furnace, ahorizontal shaft being mounted in the bearing.

References Cited in the file of this patent UNITED STATES PATENTS639,437 Robinson Dec. 19, 1899 1,852,809 Kleinow Apr. 5, 1932 1,957,965Kennedy et a1. May 8, 1934 2,011,026 Bailey et a1 Aug. 13, 19352,229,068 Frisch Jan. 21, 1941

